Solution-derived monolithic thin films with low adhesion surface

Abstract

Nanostructured thin films were synthesized using a silica-based sol-gel method. The morphology of the films was tailored by controlling the hydrolysis and crosslinking mechanisms of the tetraethyl orthosilicate precursor. Silica nanoparticle self-assembled structures and linear silica chains were crosslinked and formed monolithic nanostructured films. The self-assembly mechanism was investigated using coarse-grained molecular dynamic simulation. Three nanostructured configurations were synthesized and studied to optimize the surface features of the films and minimize the adhesion of sand particles. Surface microscopy imaging and adhesion force measurements using atomic force microscopy with an attached silica particle on the cantilever tip were performed to correlate the adhesion force and the surface structure. The solar specular reflectance of coated solar mirror samples was measured across the solar spectrum before and after the soiling test of the samples. The mechanical properties of the thin films were evaluated using nanoindentation measurements on coated substrates. The solution-derived thin film coatings can provide anti-soiling protection of solar glass in desert environments and increase the efficiency of photovoltaic and concentrated solar power installations.